I have to admit that my first reaction on reading this question here was: WTF??!!
But really, it is a good idea you've got this fixation with make-up because you'll have something else to concentrate on and take your mind of things whilst in there.
as hester well said, try and keep it minimal to avoid smudges.
another more or less valid alternative is theatre make-up, if you can get hold of some I expect is quite hard-wearing and comes in all colours and shades.
or use your normal colours but buy the really wear-proof versions of them if you can find that anywhere.
BUT remember to take your make-up bag with you, a good mirror, make-up removing wipes (easier than messing about with cleansers) and a facial spray (Evian do one I believe).
also, lighting in hospitals is awful, so you might think your make-up is OK when you look in the mirror but people around you might not.
and whatever you do, don't use any fragrance (even if you want to keep up your full maintenance routine)around the baby for the first few weeks. the same goes for new daddy.
oh, you'll look lovely, believe me. all the natural occurring hormones, adrenaline, happiness will make you look wonderful. it's all natural.
good luck with the birth pammily!